sctp: introduce sctp_dst_mtu

Which makes sure that the MTU respects the minimum value of
SCTP_DEFAULT_MINSEGMENT and that it is correctly aligned.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Marcelo Ricardo Leitner 2018-04-26 16:58:57 -03:00 committed by David S. Miller
parent 2521680e18
commit 6ff0f871c2
3 changed files with 12 additions and 9 deletions

View file

@ -600,10 +600,15 @@ static inline __u32 sctp_mtu_payload(const struct sctp_sock *sp,
return mtu ? mtu - overhead : overhead;
}
static inline __u32 sctp_dst_mtu(const struct dst_entry *dst)
{
return SCTP_TRUNC4(max_t(__u32, dst_mtu(dst),
SCTP_DEFAULT_MINSEGMENT));
}
static inline bool sctp_transport_pmtu_check(struct sctp_transport *t)
{
__u32 pmtu = max_t(size_t, SCTP_TRUNC4(dst_mtu(t->dst)),
SCTP_DEFAULT_MINSEGMENT);
__u32 pmtu = sctp_dst_mtu(t->dst);
if (t->pathmtu == pmtu)
return true;

View file

@ -1405,11 +1405,9 @@ void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
return;
/* Get the lowest pmtu of all the transports. */
list_for_each_entry(t, &asoc->peer.transport_addr_list,
transports) {
list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
if (t->pmtu_pending && t->dst) {
sctp_transport_update_pmtu(
t, SCTP_TRUNC4(dst_mtu(t->dst)));
sctp_transport_update_pmtu(t, sctp_dst_mtu(t->dst));
t->pmtu_pending = 0;
}
if (!pmtu || (t->pathmtu < pmtu))

View file

@ -242,9 +242,9 @@ void sctp_transport_pmtu(struct sctp_transport *transport, struct sock *sk)
&transport->fl, sk);
}
if (transport->dst) {
transport->pathmtu = SCTP_TRUNC4(dst_mtu(transport->dst));
} else
if (transport->dst)
transport->pathmtu = sctp_dst_mtu(transport->dst);
else
transport->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
}